The Groshong(*) catheters are popular venous access devices, in part, because they can be maintained with only weekly saline flushes. Previously data from a recent study suggested an apparent decrease in the rate of withdrawal occlusion malfunction in Groshong catheters flushed weekly with heparinized saline. However, a prospective, randomized trial is required to fully evaluate the differences between flushing with saline only versus flushing with heparinized saline. This study will randomly group up to 132 subjects to either saline alone or heparinized saline flushes. Comparisons will be made between the groups for frequency of treatment for catheter occlusion with urokinase during the first 3 months of catheterization. To date, 16 subjects have been accrued for this protocol. Interim data will be analyzed when 10 subjects have been observed for 1 month in each treatment arm of either Groshong PICC or Groshong sample groups.